Watercraft Structure, In Particular an Aquabike

ABSTRACT

Watercraft structure, in particular an aquabike, comprising a first elongated floating body ( 5 ) and a second elongated floating body ( 6 ) connected to the first floating body and arranged parallel to it spaced at a determined distance. Between two floating bodies ( 5, 6 ), furthermore, a seat ( 16 ) is provided, which can be associated to a footrest and is connected by a rod ( 26 ) to the floating bodies ( 5, 6 ), on which one or more users can sit. For increasing the lifting forces pushing against the floating bodies ( 5, 6 ), a hydrodynamic lifting transversal element ( 30 ) is provided arranged at the barycentre of the watercraft ( 101 ). The hydrodynamic lifting transversal element ( 30 ) in use has an upper surface ( 31 ) that faces the floating bodies ( 5, 6 ) and a lower surface ( 32 ) opposite to the upper surface ( 31 ).

FIELD OF THE INVENTION

The present invention relates to a watercraft structure, in particular an aquabike, for a recreational use or as means of operation or of service.

DESCRIPTION OF THE PRIOR ART

As well known, a variety exists of types of small sized watercrafts, suitable for the above described uses in lakes, in the sea or in rivers.

A kind of vessels, so-called aquabike, provides a personal watercraft for carrying a person like a motor vehicle on a road. The structural features of such vessels, and in particular the high weight, have the drawback of requiring powerful engines for sailing.

However, the use of a powerful engine, in addition to the remarkable costs, affects also the overall weight of the watercraft so that it can be laid up in a problematic way. Furthermore, the high cost limits its spread in the market.

In order to limit as far as possible the power of the engines and to reduce the overall weight of the watercraft, vessels have been designed with strong hydrodynamic features that however can only in part solve the above described drawbacks.

Also small watercrafts exist having devices that allow them to plane on the water surface, i.e. to sail at a high speed with the bottom the least possible dipped in water. Even these watercrafts provide high costs since they have sophisticated bodies and ultra-light material for reducing as far as possible the resistance against high speed.

SUMMARY OF THE INVENTION

It is therefore a feature of the invention to provide a watercraft structure, in particular an aquabike, that is light, structurally easy and cost effective.

It is another feature of the invention to provide a watercraft structure, in particular an aquabike, that can be easily disassembled in order to assist its transportation.

These and other features are accomplished with one exemplary watercraft structure, in particular an aquabike, according to the present invention, whose characteristic is that it comprises:

-   -   at least a first and a second elongated floating body, spaced         apart from and connected to each other;     -   a propelling unit suitable for thrusting in a predetermined         direction the above described first and second floating bodies;     -   at least one seat for an user;     -   a handlebar suitable for allowing the user to steer the thrust         of said propelling unit;     -   at least one hydrodynamic lifting transversal element integrally         connected to said floating bodies substantially under the         barycentre of said watercraft and suitable for increasing the         lifting forces caused by a sailing motion of said first and         second floating bodies.

In particular, the elongated floating bodies are hollow and light bodies. For this reason, the presence of the hydrodynamic lifting transversal element, allows to obtain a watercraft of minimum weight and have relevant lifting features so that lighter engines can be used.

The hydrodynamic lifting transversal element, which in use has an upper surface that faces the floating bodies and a lower opposite surface, is capable of generating a lift perpendicular to the lower surface caused by pressure difference between the two surfaces when sailing in a liquid medium.

In an exemplary embodiment of the invention, in addition to the above described first and second floating bodies that in use are substantially parallel and are arranged sideways, a third floating body is provided arranged in a central and raised position.

In all the embodiments of the invention, the user can easily manoeuvre the watercraft, both displacing its own weight, in order to bear selectively on the first or on the second floating body for changing the sailing direction, and steering the handlebar to orient the thrust of the propelling unit.

Advantageously, the propelling unit provides a outboard engine, for example of the propeller or water-jet type, mounted on a rear cross bar arranged between the first and the second floating body.

Alternatively, the propelling unit can be an inboard engine, for example of the propeller or water-jet type, connected to a frame integral to said floating bodies.

Advantageously, the first and second floating bodies are joined to the third floating body. This can be achieved, for example, by at least one strip of fabric, suitable for inflatable watercrafts, connected for example with glue, seams, snap fasteners, or the like.

In particular, the above described floating bodies are made of a material selected from the group comprised of:

-   -   stiff material, for example in metal sheet, moulded plastic;     -   inflatable material, i.e. flexible and inflatable material of         tubular shape;     -   material obtained from a combination of the two above materials.

All the embodiments of the watercraft, either of stiff type, or of inflatable type, as well as a combination thereof, can provide either stiff floating portions and inflatable central body or vice-versa. In case of inflatable floating bodies, as known they can be shrunk to a compact configuration, of minimum encumbrance in order to assist their transport.

Advantageously, in particular in case of inflatable bodies, a frame is provided comprising a plurality of stiffening longitudinal elements and constrained to said hydrodynamic lifting transversal element. The frame bears the thrust of the propelling unit, fixed to a stern cross member. The stiffening longitudinal elements can be inserted in longitudinal housings defined by the above described strips of fabric.

In an exemplary embodiment of the invention, the frame comprises the above described stiffening longitudinal elements in rows connected by means of stiffening transversal elements.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now disclosed with the following description of an exemplary embodiment thereof, exemplifying but not limitative, with reference to the attached drawings wherein:

FIG. 1 shows a top plan view of a possible exemplary embodiment of stiff type for a watercraft structure, in particular an aquabike, according to the invention;

FIG. 2 shows a perspective view of the watercraft structure, in particular an aquabike, of FIG. 1;

FIG. 3 shows a cross sectional view according to arrows III-III of the watercraft structure, in particular an aquabike, of FIG. 1;

FIG. 4 shows a top plan view of a possible exemplary embodiment of inflatable type for the watercraft structure, in particular an aquabike;

FIG. 5 shows in a rear view the watercraft structure, in particular an aquabike, of FIG. 4;

FIG. 6 shows a perspective view of a possible exemplary embodiment for a frame used for the watercraft structure, in particular an aquabike, of FIG. 4;

FIG. 7 shows an elevational side view of the watercraft structure, in particular an aquabike, of FIG. 4.

DESCRIPTION OF A PREFERRED EXEMPLARY EMBODIMENT

In figures from 1 to 3 a first exemplary embodiment is shown for a watercraft structure, in particular an aquabike, according to the present invention. It provides essentially a first elongated floating body 5 and a second elongated floating body 6 connected to the first and arranged parallel to it spaced at a determined distance. The two floating bodies 5 and 6 can be made of stiff material, for example of metal sheet or plastic material, and are thrust by a propelling unit, for example an outboard engine 50.

Between floating bodies 5 and 6, furthermore, a seat 16 is provided, which can be associated to a footrest and can be connected by a rod 26 to floating bodies 5 and 6, on which one or more users can sit. Watercraft 101 can be steered by a handlebar 15, which is also connected to floating bodies 5 and 6 by a rod 25.

For increasing the lifting forces, which when sailing at enough speed act against floating bodies 5 and 6, an hydrodynamic lifting transversal element 30 is provided immersed under the barycentre of watercraft 101. Transversal element 30 in use has an upper surface 31 that faces floating bodies 5 and 6 and a lower surface 32 opposite to the upper surface 31, both of suitable profile, preferably with a wing-like cross section. When hydrodynamic lifting transversal element 30 is put in a flow, it is subject to a lifting force perpendicular to the lower surface 32 caused by a pressure difference between the two surfaces. By virtue of this lifting force a watercraft can be designed that is light, easily manoeuvrable and not requiring a powerful propelling means. Owing to the lightness and the catamaran configuration, the watercraft requires low powered engines and assures good performances. In fact, when watercraft 101 speeds up on water, the hydrodynamic forces allow reducing the ratio length/width of the elongated floating bodies 5 and 6 and the resistance owing to this ratio also decreases. Thus, a decrease of power demand derives, owing to the presence of hydrodynamic lifting transversal element 30, which holds during the movement most of the weight of watercraft 101. More in detail, the lift of transversal element 30 reduces the weight of watercraft 101 relative to water, and therefore the resistance against movement.

The lower profile of floating bodies 5 and 6 can be substantially V-shaped as in most of planing watercrafts. Furthermore, one or more skids or steps can be provided to assist the separation from water in phase of acceleration, causing the watercraft 101 to plane much more quickly and at a lower speed.

An inflatable exemplary embodiment of the watercraft can also be provided, as shown in figures from 4 to 7, where a third elongated body 7, which is also inflatable, is arranged in a central position and raised with respect to floating bodies 5 and 6, that are located sideways. Even in this exemplary embodiment of the invention, the user can easily manoeuvre the watercraft 1 simply displacing its weight in order to allocate more weight either on the first or on the second floating body for adjusting the sailing direction; of course, the thrust of engine 50 can be steered as desired.

If floating bodies 5, 6 and 7 are of the inflatable type, a plurality of elongated stiffening longitudinal elements 21 and 23 is provided bearing the thrust of propelling unit 50 and also supporting hydrodynamic lifting transversal element 30 (FIG. 5).

For increasing the stiffness of watercraft 1, side floating bodies 5 and 6 can be connected integrally to central floating body 7, for example by means of glue, seams, etc. Furthermore, each side floating body 5, or 6 can be constrained to elongated central body 7, for example, by at least one strip of fabric 26, of material suitable for inflatable vessels, having a portion constrained to a side floating body 5, or 6, and a portion constrained to central floating body 7. The strip of fabric 26 can be provided with mutual engagement elements, for example snap fasteners 35 or other, associated to corresponding engagement elements 36 provided on the two floating bodies. The strips of fabric 26 can also act as sheath for stiffening longitudinal elements 21 and 23.

In this inflatable exemplary embodiment a frame 20 is provided shown in FIG. 6 and comprising stiffening longitudinal elements 21-23 as described hereafter. In particular, stiffening longitudinal elements 21 are linked by a shaped front element 22 arranged on a first plane parallel to the water plane of watercraft 1. Similarly, stiffening longitudinal elements 23 are linked by a shaped front element 24. Elements 22 and 24 are interconnected by means of rods 56.

In this case, the third floating elongated bodies 7 has a seat 16 and handlebar 15 can be mounted on a cross support member 25 that engages the frame 20 of watercraft 1. Handlebar 15 can, in particular, being connected, for example, by a transmission cable 27 to propelling unit 50 for steering the thrust in a desired direction. Thanks to the structural features above described, the user can easily manoeuvre watercraft 1, either displacing the weight allocating it more on first floating body 5 or on second floating body 6, or steering the thrust.

Approximately, static side steadiness is responsive to the distance from the barycentre of two elongated floating bodies 5 and 6 and is zeroed only for sudden leaning beyond 30°. An inclination of the user in an opposite direction, in a way similar to a motorcycle, restores quickly the steadiness of the watercraft and avoids tilting even for stronger leanings. This allows the use of the watercraft also for sport and acrobatics.

The embodiment shown in particular in FIG. 5 provides floating bodies 5-7 of inflatable that can be easily deflated up to a shrunk configuration, of minimum encumbrance and easily transportable. Furthermore, the presence of hydrodynamic lifting transversal element 30 allows increasing remarkably the lifting features of the watercraft 1 and, therefore, using engines 50 of limited power. This determines an overall weight and cost of watercraft 1 remarkably less than in the prior art.

A watercraft 101, or 1, as above described allows quick and easy movements in water with very contained costs and size. The structural features of watercraft 1, or 101, according to the invention, are particularly suitable for recreational use, but also as transportation means in inner or coastal waters, or as tender for larger watercrafts, as well as for use as means for patrolling or for emergency in seaside resorts.

The foregoing description of a specific embodiment will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt for various applications such an embodiment without further research and without parting from the invention, and it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiment. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. 

1. Watercraft structure, in particular an aquabike, characterised in that it comprises: at least a first and a second elongated floating body, spaced apart from and connected to each other; a propelling unit suitable for thrusting in a predetermined direction the above described first and second floating bodies; at least one seat for an user; a handlebar suitable for allowing the user to steer the thrust of said propelling unit; at least one hydrodynamic lifting transversal element integrally connected to said floating bodies substantially under the barycentre of said watercraft and suitable for increasing the lifting forces caused by a sailing motion of said first and second floating bodies.
 2. Watercraft structure, according to claim 1, wherein said hydrodynamic lifting transversal element in use has an upper surface that faces said floating bodies and a lower opposite surface and is capable of generating a lifting force perpendicular to said lower surface delivered by pressure difference between said two surfaces when put in a flow.
 3. Watercraft structure, according to claim 1, where in addition to said first and second floating bodies, which in use are substantially parallel and are arranged sideways, a third floating body is provided arranged in a central and raised position.
 4. Watercraft structure, according to claim 1, wherein said propelling unit is selected from the group comprised of: an outboard engine; an inboard engine.
 5. Watercraft structure, according to claim 1, wherein said propelling unit is selected from the group comprised of: a propeller type unit; a water-jet type unit.
 6. Watercraft structure, according to claim 3, wherein said side floating bodies are engaged with said central floating body.
 7. Watercraft structure, according to claim 6, wherein said side floating bodies are engaged to said central floating body by at least one strip of fabric having a portion constrained to a said side floating body and a portion constrained to said central floating body.
 8. Watercraft structure, according to claim 7, wherein said strip of fabric is constrained to each of said floating bodies by a connecting means selected from the group comprised of: glue, seams, mutual engagement elements or combination thereof.
 9. Watercraft structure, according to claim 1, wherein said floating bodies are selected from the group comprised of: stiff floating bodies; inflatable floating bodies; a combination of stiff and inflatable floating bodies.
 10. Watercraft structure, according to claim 1, wherein said floating bodies are of inflatable type and a frame is provided comprising a plurality of stiffening longitudinal elements constrained to said hydrodynamic lifting transversal element.
 11. Watercraft structure, according to claim 7, wherein said stiffening longitudinal elements are inserted in longitudinal sheaths defined by said strips of fabric.
 12. Watercraft structure, according to claim 1, wherein said frame comprises said stiffening longitudinal elements in rows connected by means of stiffening transversal elements. 